P0674 on Chevrolet
Cylinder 4 Glow Plug Circuit
P0674 on Chevrolet vehicles indicates cylinder 4 glow plug circuit. Au7o has documented this code across 1 Chevrolet model — most commonly on Silverado 3500HD. This is a diesel engine code. Glow plugs preheat each cylinder so the diesel fuel ignites reliably, especially during cold starts. P0674 means the glow plug control system detected an electrical fault in the cylinder 4 glow plug circuit — commonly an open circuit, a short, or resistance outside the normal range. The typical symptoms are difficult cold starting, rough running until the engine warms, more startup smoke, and possibly an illuminated glow plug indicator. Typical repair costs on Chevrolet range from $200 to $800, depending on the specific model and root cause.
Common Causes of P0674
- •Failed (open or shorted) cylinder 4 glow plug
- •Damaged or corroded glow plug wiring/connector
- •Loose or corroded glow plug terminal/strap
- •Faulty glow plug relay or control module
- •Broken or chafed harness to the glow plug
- •Poor ground or low supply voltage to the circuit
P0674 on Chevrolet by Model
Chevrolet Silverado 3500HD(1 issue)
- Glow Plug Failure and Hard Cold Starting2001-2020
Glow plugs fail causing difficult cold weather starting. Can also swell and break during removal, requiring extraction. Glow plug module can also fail.
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View P0674 across all makes →Frequently Asked Questions
What does P0674 mean on Chevrolet?▼
P0674 stands for "Cylinder 4 Glow Plug Circuit." This is a diesel engine code. Glow plugs preheat each cylinder so the diesel fuel ignites reliably, especially during cold starts. P0674 means the glow plug control system detected an electrical fault in the cylinder 4 glow plug circuit — commonly an open circuit, a short, or resistance outside the normal range. The typical symptoms are difficult cold starting, rough running until the engine warms, more startup smoke, and possibly an illuminated glow plug indicator. On Chevrolet specifically, this code is documented across 1 model.
What causes P0674 on Chevrolet vehicles?▼
Common causes on Chevrolet: Failed (open or shorted) cylinder 4 glow plug, Damaged or corroded glow plug wiring/connector, Loose or corroded glow plug terminal/strap, Faulty glow plug relay or control module, Broken or chafed harness to the glow plug. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0674 on a Chevrolet?▼
Repair costs on Chevrolet range from $200 to $800, depending on the specific model and root cause.
Which Chevrolet models have P0674 documented?▼
Au7o has documented P0674 on 1 Chevrolet model: Silverado 3500HD.